1. Field of the Invention
The present invention generally relates to night vision infrared imaging systems as used in helicopters, e.g. night vision goggles.
2. Description of Prior Art
Beginning September 1990, a system was built and subsequently flight tested using a projected cueing technique as a warning in terrain avoidance. The services in this and other countries have tested prototype night vision sensors to detect and display small obstacles such as wires and poles. These types of obstacles are particularly hazardous to low flying helicopters and certain fixed wing aircraft that fly similar reconnaissance missions. These sensors include both laser systems such as the British LOCUS CO.sub.2 laser light detection and ranging system (lidar) and conventional microwave radars such as the french ROMEO radar. The U.S. Army has recently awarded a contract for a diode laser lidar under the name of OASYS. All these systems employ some form of warning system inside the cockpit, which may include an audible alarm and/or an indication on a heads-up or heads-down display. These indirect warning systems have the limitation that while the obstacle location is indicated, the hazard may not be seen or correctly evaluated by the pilot. There is a need for a cueing system that interacts directly and visually with the pilot to better locate and identify an obstacle in the shortest possible time.